Problem:
vim.glob.to_lpeg() errors when patterns contain numeric literals
(like the '1' in '.ps*1') because LPeg interprets numeric strings
as indexed grammar rule references. For example:
vim.glob.to_lpeg('.ps*1')
E5108: Lua: rule '1' undefined in given grammar
Solution:
Prefix all rule names with '_' in the end_seg() function to prevent
literal numbers from being interpreted as LPeg indexed rules. This
ensures pattern components like '1', '2', etc. are treated as
regular rule names rather than special references.
|vim.glob.to_lpeg()| uses a new LPeg-based implementation (Peglob) that
provides ~50% speedup for complex patterns. The implementation restores
support for nested braces and follows LSP 3.17 specification with
additional constraints for improved correctness and resistance to
backtracking edge cases.
This change fixes an issue where glob patterns like `{a,ab}` would not
match `ab` because the first option `a` matches, then the end of the
string is expected but `b` is found, and LPeg does not backtrack to try
the next option `ab` which would match. The fix here is to also append
the rest of the pattern to the generated LPeg pattern for each option.
This changes a glob `{a,ab}` from being parsed as
("a" or "ab") "end of string"
to
("a" "end of string" or "ab" "end of string")
Here, matching against `ab` would try the first option, fail to match,
then proceed to the next option, and match.
The sacrifice this change makes is dropping support for nested `{}`
conditions, which VSCode doesn't seem to support or test AFAICT.
Fixes#28931
Co-authored-by: Sergey Slipchenko <faergeek@gmail.com>
refactor(lsp): move glob parsing to vim.glob
Moving the logic for using vim.lpeg to create a match pattern from a
glob into `vim.glob`. There are several places in the LSP spec that
use globs, and it's very useful to have glob matching as a
generally-available utility.
